Bath for extracting products from wood.



UNITED sATEs PATENT OFFICE.

FREDERICK POPE, MOUNT IELIEASAN'JZ, GEORGIA, ASSIGNOR TO SOUTHERN MANU- FACTURING COMPANY.* .OF PITTSBURG', PENN SYLVAN'IA, A CORPORATION PENNSYLVANIA.

No Drawing. j

BATH FOR EXTRAcir Nc'PnonUoTs FROM 001).

To all whom itimay concern:

centage of its products.

The bath may be variously combined and the essential ingredients of the same arepitch and pine oil and .preferably some other maintaining ordinary pine tar at a boiling temperature until practically all the volatile constituents thereof are driven off as vapor. Care must be taken not to destructively distil thetar and in no case should the temperature exceed 430 degrees Fahren heit, and as a rule it is not necessary to em ploy as high a temperature as that. The boiled tar is then washed by adding lime to the hot tar and introducingsteam into the bottom of the vessel. The lime combines with thephenols and other impurities,

forming compounds which are carried to the top where'they may be removed with a skimmer. The boiling is continued until when a. stick pin is plunged into the hot bath and then intocold water the tar will adhere thereto and be brittle. Lime is introduced as long as there are any acids,

which will react with it. This washed tar is odorless, very hard and brittle and has a low melting'point. 'It has, however,- avv comparatively high specific heat so that .it

can give up a large number of-heat-units for a glven drop in: temperature.

The pine oil used is the standard pine oil of commerce. It is the second product which is obtained in refining distillate of fat dead pine, that is, light wood which has been distilled at a temperature of over 360 degrees and under400 degrees Fahrenheit 7 Specification of Letters Patent. PatentedfJ 3,11; 25, 1910, Application filed May 16, 1908. SerialNo; 433,230.

by one of the commercial methods. The residuum after this oil has been made is the soft pitch which isused. Its character varies more or less with the process by which it is made.

The pine oil is a thin and very mobile liquid. It soaks well into the wood softening the'cellular structure, so as to facilitate .the action of the heat on the products which are to be extracted. In other Words, it possesses high searching qualities.

r The advantages of the soft pitch are that it makes the bathmobile so that itis not likely to readily solidify. It also has a high searching action on the wood so as to give a larger yieldof the products in a short time. This soft'p'itch is'prOduced in the distillation of the productsv obtained from the pine'wood.

In place-of the washed tar I may make use of hard pitch oreven rosin. Neither hard pitch nor rosin isthe'equivalent of washed tar, but they have properties which permit their use and which make them possible substitutes for washed tar.

The hard pitch used is the standard 'aiticle of commerce made by the American Naval Stores Company and sold under that name and is the. residue leftwhen rosin is destructively distilled until the rosin spirit and-the first run of rosin oil have been removed.

These several ingredients have been and can be joined in various proportions.

amples of a satisfactory bath are the folv lowing WVashed tar 70 pine oil 10. parts. Hard pitch 45 pine oil 10 parts.

parts, soft pitch 20 parts, parts, soft pitch 45 parts,

Washed tar 10 parts, hard pitch 45 parts,

ter' of the wood being treated and also with the temperature or season of the year. .For instance, in the summer it is possible to use a bath having a larger percentage of Washed tar or hard pitch and a smaller percentage of soft pitch than can be used in the winter. The soft pitch and the pine oil arethe principal searching agents giving fluidity to the bath. The pine oil has the highest search Hard pitch 50 parts, soft pitch 50 parts.

These baths, however, have not the search ;ing qualities of the baths containing pine oil.

The bath described', and especially when it contains washed tar, is capable of being raised to a very high temperature without serious injury thereto. It has been found that such bath can be heatedas high as 400 degrees Fahrenheit. This high temperature provides for the extraction from the wood of a larger percentage of products than can be obtained at a lower temperature.

In using the bath described it IS heated to a high temperature and the wood to be treated is immersed the rein,the heat and the searching qualities of the bath causing the volatilization of the products of the wood, which products are afterward separated from the bath in any suitable way, such as agitating the bath by introducing steam thereinto. During use, it will be found desirable to renew some of the ingredients regularly from time to time, such as adding thereto from time to time a quantity in the Patent Qfiicef [S-EAL] Correction in Letters Patent No- 947,420.

of soft pitch obtainedin distillation of the products extracted by the bath, and also regularly addingthereto alesser quantity of ine oil.

\Vhat I claim is l. A bath for extracting products from wood, comprising pitch, pine oil and one of the harder products obtained in the distillation of products from pine wood.

2. A bath for extracting products from wood,co1nprising pitch, pine oil and washed tar.

3. A bath for extracting products from wood, comprising soft pitch and one of the harder products obtained in the distillation of products obtained from pine wood, the ioftl;1 pitch constituting at least 10%. of the 4;. A bath for extracting products from wood, comprising washed tar, soft pitch, and pine oil,in substantially the proportions specified.

5. A bath for extractingproducts from wood, comprising soft pitch, pine oil, and one of the harder products obtained in the distillation of products from wood, the pine pJil kponstitutingapproximately 10% of the my name.

FREDERICK POPE.

\Yitnesses i J. I1, ROE, J. D. Porn. .Tr.

It is hereby certified that in Letters Patent No. 947,420, granted January 25, 1910, upon the application of Frederick Pope, of Mount Pleasant, Georgia, for an improvement in Baths for Extracting Products from Wood an error appears in theprinted specification requiring correction as follows: Page 1, line 42, the word pin should be stricken out; and that the said Letters Patent should he read "with this correction therein that same may conform to the record of the case Signed and sealed this 8th day of February, 1)., 1910.

E. B. MOORE,

. (Jbmmissz'oner of Patents.

In testimony whereof I have hereunto set i 

